headspace threads...

glokmunkee · May 18, 2009, 05:42 PM

I am looking for information on using the bullet shouldered against the rifling as headspace for my 9mm para. I know that it is not possible with rn as they wont feed into the mag but the hp I am using is short enough to do this and feed and function. so are there any drawbacks in doing this or has it been discussed already. ( i didnt know how to word this in a search... bullet shouldering ?? ) reason being that head space with commercial brass is a waste of time as the case isnt even close to being long enough for my breech (6944 s&w) and in leu of having it cut down, there will still be some room for variants as I have no plans on trimming every case that goes in to that gun. thanks in advance

Don P · May 19, 2009, 01:19 PM

No reason in the world to have to trim handgun brass unless you are triming 357mag to 38spl length or 44mag to 44spl length. I have loaded over 10,000 rounds and have yet to trim 1 case. If it chambers and will feed from the mag all should be good. From what you explained it sounds as if you are not seating you round nose deep enough. I use 125gr round nose lead cast and it will feed in all my 9mm's. Matter of fact round nose lead cast is all I use in 38spl, 357mag, 9mm, 40s&w, and 45acp

glokmunkee · May 19, 2009, 01:44 PM

i'll be nice.... umm thanks?

glokmunkee · May 19, 2009, 01:54 PM

well, not so fast. "no reason in the world"? really? c'mon mr ive loaded 10000 hundert gazillion rounds.... why then would I be looking to cut down a 9mm mag case to make proper headpsaced match rounds for my gun. "custom reloading" sure sounds like a reason to me., now whether it is a never shoot or do nothing but post on a bb with a sandwich in my mouth who cant read cause the tin foil is scrambling your brain need to go post your comment that has nothing to do with my question elsewhere in your world or not but you just continue to pump out those generic little paper poppers and like I said,

umm thanks.
PS while it may sound like I am not seating my bullet deep enough .. well i am seating it where I choose to seat it what i am to ... oh nevermind

Don P · May 19, 2009, 01:56 PM

Lets get this straight you DON"T HAVE TO BE NICE ON MY PART. From your reply I'll assume your question is not answered.

Don P · May 20, 2009, 07:34 AM

Ah yes, the only thing personal attacks will get you here on TFL is either a pm from the moderators or banned from posting. Never said I had all the answers and from your post neither do you for your "custom match rounds". No need to reply to this or my previous post. No need to dig a deeper hole for yourself with regards to the moderators. Hopefuly some one will be able to answer your question.

Johnny Guest · May 20, 2009, 08:40 AM

glokmunkee - -

It may be that you're making this a bit more complicated than it needs be. There may be some advantages to seating a RIFLE bullet so that it touches, or nearly touches, the rifling, it is impractical with most if not all auto pistol cartridges.

There are two ways I know of arriving at a proper seating depth for a given round nose bullet in the 9mm Parabellum ctg.

1. Look in the manual or manufacturer's literature for THAT particular bullet and get their specification for COL (cartridge overall length.) For instance, the Speer item number 3995, a 115-gr. TMJ round nose (plated) bullet. Their manual specifies a COL of 1.135". To achieve this, back out the seating stem of your die. Just barely start the bullet into the case. Progressively screw in the seating stem to seat the bullet deeper and deeper until the 1.135 COL is reached. You'll need a caliper in order to measure this accurately. Once you reach it, adjust the case body to put the desired amount of constriction on the case mouth. Check this by either using a case gauge or remove the barrel from your pistol and drop the loaded round into the chamber to make sure it'll seat properly.

2. You can manage quite well even without a caliper. Take a factory cartridge loaded with such a bullet and use it to set your seating die. Back out the seating stem and the locking ring of the die. Place the cartridge in the shell holder and raise it all the way up. Screw the die body in until the body is snug against the case. Then screw the stem in until it is snug against the bullet nose. Lock everything in place and load a round. Check the resulting round for proper fit, make any fine adjustments, and you're in business.

Neither of these procedures is really complicated in practice. You can set your seating die by eaither method, in far less time than it took to type them. Either way, you now have a cartridge that will work through your magazine, will feed properly, and is not seated so deeply as to have excessive pressure, assuming you're using a published load of powder.

Best,
Johnny

Jim Watson · May 20, 2009, 08:59 AM

I have loaded a lot of .45 ACP cast SWC and Adams (RN with a shoulder) bullets to where headspace is controlled by the shoulder contacting the origin of the rifling. I don't do it with jacketed bullets because there are few of them of a shape that will allow it but mainly because it does not do much good.

If I wanted to do so with 9mm, I would find a SWC bullet and go ahead. I don't think it will help anything with a JHP but it is your gun, have at it. It will increase chamber pressure a bit, but if you are not loading to the maximum, it won't be enough to matter.

glokmunkee · May 20, 2009, 03:19 PM

This was answered elsewhere but thanks. Ummm, thanks but I may not know how to type but I do know how to seat a bullet, and i am curious ... How would I have acheived those numbers if I didn't have a set of calipers? You must think I have some good eyes!! Thank you but I dont. I think I have found a new signature... "there are reasons to do things.. even if YOU cant see the reasoning behind it!"... I like it.! Furthermore i am prepping these hp rounds to be fired into ballistics gel, which is six inches tall at 10 yards. I have never loaded these before and I am sure you all have your own methods for ensuring that the first shot hits without a keyhole but I want to have my own way of doing it... and it was just a question. geez

ear-ingun · May 20, 2009, 04:28 PM

glockmonke

You must be from Minneapolis!

post #10
http://www.thefiringline.com/forums/...d.php?t=354934

glokmunkee · May 20, 2009, 04:51 PM

I guess I am. wow. I haven't been on a forum in years and I have to admit I ph.text alot but I didn't know i had to open the text book and learn how to write and spell again. who uses that anymore.. ??

HA im jokin. sorry if I come off crude but, well, it is kinda like in a real conversation with people. I use slang and if I am talking among friends of a subject and an evesdropper someone pipes in with something unrelated.... what would you do?
(oops-->)that is kinda what it is like when they poke in just to find a place to deposit two cents. Anyway thanks for the help if I dont get kicked off of here then maybe we can have some fun, learn some stuff, and come up with some good recipes. Enough of this "just do what the book says and keep your head down young man!!" Its not like if I cant post here then I will stop shooting and loading! " 'Cause... I like shootin' though."

glokmunkee · May 21, 2009, 04:59 AM

I know you shoot .45 but can I ask if you shoot 9mm and have any SWC .355 on hand? It would be nice to know the length of that bullet. Would it be a 125gr? I would like to know how deep in the case the bullet will seat pushing the ogive out that far. There is no way to get a round nose that far out if fails at the mag!

I have found that not exactly touching should serve the same purpose of reducing what I call the funnel effect when the bullet enters the bore. (which is what i come to be concerned with as a cause of keyholes? not barrel realted of course) I have fired several different depths and loads and am not able to replicate one but I havent pushed the envelope either. But do i plan to load up some more aggressive rounds. Do keyholes become a problem at higher velocities or lower ones? I only have so many of these bullets and I dont want to spin em off in the dirt. Thanks.

Sport45 · May 21, 2009, 05:31 AM

Keyholing with handgun rounds is generally a result of using a bullet that doesn't have enough diameter to engage the rifling. Using 9mm bullets in a .38 special comes to mind. HBWC can also keyhole if loaded backward and fired more than 10 yards or so because the heavy end wants to be in front. I suppose a barrel that is leaded to the point of the rifling being invisible to the bullet could do it, but you'd have bigger problems then.

Keyholing is more often seen in rifles when the rifling twist rate is not adequate to stabilize the bullet.

I don't believe you will experience keyholing with your 9mm as long as you are using .355" jacketed or .356" cast bullets. Seating depth will have no effect on this. A 6" target at 10 yards shouldn't be a problem and different seating depths will not put you off a target that size.

The normal cautions apply if you are shooting cast bullets in a Glock with polygonal rifling.

glokmunkee · May 21, 2009, 05:42 AM

Good news! Thanks you caught me too. I said .355 i got them backwards.

Sorry. But you raise a question. I understand that I will more than likely not ditch any rounds but you said that keyholes occur when there is not enough rifling to stabilize the bullet, well twist rate to be precise. So are you saying the rifling is not tight enough for that bullet at that velocity but would be at another? This in my mind relates to my short barrel. Reducing the stability of the bullet. I dont want any even slightly sideways. Wasted energy. Would I be able to tell from the gel?

Sport45 · May 21, 2009, 05:47 AM

The twist rate is a measure of how many inches of barrel length it takes for one complete revolution of the bullet. For instance, AR15's can be set up with anything from 1 turn in 12 inches (great for short, light bullets) to 1 in 7 (necessary to stabilize long, heavy bullets).

Handgun bullets don't vary enough in length that I've ever seen the twist rate considered to be a factor.

The length of the barrel really has nothing to do with accuracy.

glokmunkee · May 21, 2009, 06:14 AM

I agree to the point that the barrel is just a starting point and the design of the bullet has more to do with accuracy after removing the human factor. The barrel length is debatable. I am not sure that I agree with you on that. I believe that there is an optimum barrel length for any bullet as well as velocity. As in fine tuning. Changing these variables requires compensation to get similar results. Not in target rounds but performance loads. To get the best your gun has to offer you for what it was designed for. It just seems that there are too many variables for it not to matter.

Jim Watson · May 21, 2009, 07:27 AM

I do not have any 9mm SWCs, the place I used to get them from is out of business. Meister makes a 150 grain .356" SWC that is probably from the same number mould. I would not want one as light as 125 grains. The most keyholing and generally poor accuracy I have seen is from lightweight cast 9mm bullets.

People worry too much about rifling twist in standard calibers. Most European 9mms have a 10" twist, many American guns have 16". Both do ok. Ed Harris had Barsto make a Browning barrel with the 18.75" twist of a .38 Special and it shot better than either.

brickeyee · May 21, 2009, 08:41 AM

Unless you have fired thousands of practice rounds and can reliably hold on a 50 yard bullseye target to a few inches you are wasting tour time.

It takes a long time to develop the proficiency needed to worry about things like bullets touching lands in a handgun affecting accuracy.

Case length is easier to control if you are accurate enough to need it.

Sport45 · May 21, 2009, 08:48 AM

Quote:

The barrel length is debatable.

Okay, maybe longer barrels are less accurate. It seems like you'd want the bullet to spend the least time possible in that vibrating tube.

brickeyee · May 21, 2009, 03:16 PM

Longer barrels improve sight radius if you are using iron sites.

That alone improves accuracy since it reduces aiming error.

glokmunkee · May 21, 2009, 05:43 PM

So am I over simplifying to say that by increasing the twists per inch in a given length of barrel is (other than the actual pyhsics) like making a longer barrel out of a shorter one? This could indicate there is a given spin rate for a bullet too.

Sport45 · May 21, 2009, 08:36 PM

Let me google that for you.

The Greenhill Formula is generally used to select "optimum" twist rate and it is a function of bullet length. And no, changing twist does not change the effective length of a barrel. Barrel length helps determine velocity and little else. As Brickeyee mentioned, handgun barrel length affects sighting if you use the factory sights. But adding barrel length that just sticks out the front of and autoloading pistol will not help accuracy.

glokmunkee · May 22, 2009, 06:04 AM

Thanks! Thats a new one for me. I found some great sites that way! Unfortunately it has raised more questions than answers but I did find some answers luckily.
The worst one ping ponging in my head is that a rifle bbl twist rate is discussed as one twist in so many inches. It is the same for my pistol. However a rifle has a 20 something inch barrel for the bullet to be supported as it turns a complete revolution or even two. Mine has 3.5 ". Thats like 3/8ths of a revolution in the barrel. I know theoretically at 8 inches the bullet will have turned one time whether in the barrel or not. Then the post that a barsto with increased twist rate helped accuracy and was done for a pro shooter.
Barsto wont touch S&W centerfires anymore. I would like to have some barrels built, but. I think it would make a difference.

(mm's can get really flingy out around 25 yrds and more at my power factor and makes me think of the cheap cross bows they sell at guns shows; how it flings the bolt and the fletch end kicks out to the side. Of course it straightens out. ) I would rather not up the power factor i like my recoil where it is.

brickeyee · May 22, 2009, 08:50 AM

Quote:

Then the post that a barsto with increased twist rate helped accuracy and was done for a pro shooter.

Increasing twist will only affect accuracy if the twist rate was marginal for the bullet length/weight.

If the bullets are perfect using a faster than required twist would have no effect.

Since no bullet is perfectly made using a higher than required twist rate will allow any imbalance in the bullet to become more important.

You are dealing with thousands of RPM here.
The forces generated by even the slightest defect can be significant.

Jim Watson · May 22, 2009, 09:33 AM

Actually, that was a Barsto with a decreased twist rate.

If you want a really minimal twist, Schuemann will make you a 9mm/.38 Super barrel with a 35" twist rate for light bullets - under 135 grains, they say.

May 19, 2009, 01:19 PM	#2
Don P Senior Member Join Date: December 17, 2005 Location: Swamp dweller Posts: 6,187	No reason in the world to have to trim handgun brass unless you are triming 357mag to 38spl length or 44mag to 44spl length. I have loaded over 10,000 rounds and have yet to trim 1 case. If it chambers and will feed from the mag all should be good. From what you explained it sounds as if you are not seating you round nose deep enough. I use 125gr round nose lead cast and it will feed in all my 9mm's. Matter of fact round nose lead cast is all I use in 38spl, 357mag, 9mm, 40s&w, and 45acp __________________ *NRA Life Member, NRA Chief Range Safety Officer, NRA Certified Pistol Instructor,, USPSA & Steel Challange NROI Range Officer, ICORE Range Officer, ,MAG 40 Graduate* *As you are, I once was, As I am, You will be.*

May 19, 2009, 01:44 PM	#3
glokmunkee Member Join Date: April 25, 2009 Posts: 50	i'll be nice.... umm thanks? __________________ Gimme Th'm Nannerz

May 19, 2009, 01:54 PM	#4
glokmunkee Member Join Date: April 25, 2009 Posts: 50	well, not so fast. "no reason in the world"? really? c'mon mr ive loaded 10000 hundert gazillion rounds.... why then would I be looking to cut down a 9mm mag case to make proper headpsaced match rounds for my gun. "custom reloading" sure sounds like a reason to me., now whether it is a never shoot or do nothing but post on a bb with a sandwich in my mouth who cant read cause the tin foil is scrambling your brain need to go post your comment that has nothing to do with my question elsewhere in your world or not but you just continue to pump out those generic little paper poppers and like I said, umm thanks. PS while it may sound like I am not seating my bullet deep enough .. well i am seating it where I choose to seat it what i am to ... oh nevermind __________________ Gimme Th'm Nannerz

May 19, 2009, 01:56 PM	#5
Don P Senior Member Join Date: December 17, 2005 Location: Swamp dweller Posts: 6,187	Lets get this straight you DON"T HAVE TO BE NICE ON MY PART. From your reply I'll assume your question is not answered. __________________ *NRA Life Member, NRA Chief Range Safety Officer, NRA Certified Pistol Instructor,, USPSA & Steel Challange NROI Range Officer, ICORE Range Officer, ,MAG 40 Graduate* *As you are, I once was, As I am, You will be.*

May 20, 2009, 07:34 AM	#6
Don P Senior Member Join Date: December 17, 2005 Location: Swamp dweller Posts: 6,187	Ah yes, the only thing personal attacks will get you here on TFL is either a pm from the moderators or banned from posting. Never said I had all the answers and from your post neither do you for your "custom match rounds". No need to reply to this or my previous post. No need to dig a deeper hole for yourself with regards to the moderators. Hopefuly some one will be able to answer your question. __________________ *NRA Life Member, NRA Chief Range Safety Officer, NRA Certified Pistol Instructor,, USPSA & Steel Challange NROI Range Officer, ICORE Range Officer, ,MAG 40 Graduate* *As you are, I once was, As I am, You will be.*

May 18, 2009, 05:42 PM	#1
glokmunkee Member Join Date: April 25, 2009 Posts: 50	headspace threads... I am looking for information on using the bullet shouldered against the rifling as headspace for my 9mm para. I know that it is not possible with rn as they wont feed into the mag but the hp I am using is short enough to do this and feed and function. so are there any drawbacks in doing this or has it been discussed already. ( i didnt know how to word this in a search... bullet shouldering ?? ) reason being that head space with commercial brass is a waste of time as the case isnt even close to being long enough for my breech (6944 s&w) and in leu of having it cut down, there will still be some room for variants as I have no plans on trimming every case that goes in to that gun. thanks in advance Last edited by glokmunkee; May 18, 2009 at 06:15 PM.

May 20, 2009, 08:40 AM	#7
Johnny Guest Moderator in Memoriam Join Date: August 28, 1999 Location: North Texas Posts: 4,123	Seating length for 9x19mm RN bullets glokmunkee - - It may be that you're making this a bit more complicated than it needs be. There may be some advantages to seating a RIFLE bullet so that it touches, or nearly touches, the rifling, it is impractical with most if not all auto pistol cartridges. There are two ways I know of arriving at a proper seating depth for a given round nose bullet in the 9mm Parabellum ctg. 1. Look in the manual or manufacturer's literature for THAT particular bullet and get their specification for COL (cartridge overall length.) For instance, the Speer item number 3995, a 115-gr. TMJ round nose (plated) bullet. Their manual specifies a COL of 1.135". To achieve this, back out the seating stem of your die. Just barely start the bullet into the case. Progressively screw in the seating stem to seat the bullet deeper and deeper until the 1.135 COL is reached. You'll need a caliper in order to measure this accurately. Once you reach it, adjust the case body to put the desired amount of constriction on the case mouth. Check this by either using a case gauge or remove the barrel from your pistol and drop the loaded round into the chamber to make sure it'll seat properly. 2. You can manage quite well even without a caliper. Take a factory cartridge loaded with such a bullet and use it to set your seating die. Back out the seating stem and the locking ring of the die. Place the cartridge in the shell holder and raise it all the way up. Screw the die body in until the body is snug against the case. Then screw the stem in until it is snug against the bullet nose. Lock everything in place and load a round. Check the resulting round for proper fit, make any fine adjustments, and you're in business. Neither of these procedures is really complicated in practice. You can set your seating die by eaither method, in far less time than it took to type them. Either way, you now have a cartridge that will work through your magazine, will feed properly, and is not seated so deeply as to have excessive pressure, assuming you're using a published load of powder. Best, Johnny

May 20, 2009, 08:59 AM	#8
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,543	I have loaded a lot of .45 ACP cast SWC and Adams (RN with a shoulder) bullets to where headspace is controlled by the shoulder contacting the origin of the rifling. I don't do it with jacketed bullets because there are few of them of a shape that will allow it but mainly because it does not do much good. If I wanted to do so with 9mm, I would find a SWC bullet and go ahead. I don't think it will help anything with a JHP but it is your gun, have at it. It will increase chamber pressure a bit, but if you are not loading to the maximum, it won't be enough to matter.

May 20, 2009, 03:19 PM	#9
glokmunkee Member Join Date: April 25, 2009 Posts: 50	This was answered elsewhere but thanks. Ummm, thanks but I may not know how to type but I do know how to seat a bullet, and i am curious ... How would I have acheived those numbers if I didn't have a set of calipers? You must think I have some good eyes!! Thank you but I dont. I think I have found a new signature... "there are reasons to do things.. even if YOU cant see the reasoning behind it!"... I like it.! Furthermore i am prepping these hp rounds to be fired into ballistics gel, which is six inches tall at 10 yards. I have never loaded these before and I am sure you all have your own methods for ensuring that the first shot hits without a keyhole but I want to have my own way of doing it... and it was just a question. geez __________________ Gimme Th'm Nannerz

May 20, 2009, 04:28 PM	#10
ear-ingun Member Join Date: June 6, 2007 Location: Rockies Posts: 28	glockmonke You must be from Minneapolis! post #10 http://www.thefiringline.com/forums/...d.php?t=354934

May 20, 2009, 04:51 PM	#11
glokmunkee Member Join Date: April 25, 2009 Posts: 50	I guess I am. wow. I haven't been on a forum in years and I have to admit I ph.text alot but I didn't know i had to open the text book and learn how to write and spell again. who uses that anymore.. ?? HA im jokin. sorry if I come off crude but, well, it is kinda like in a real conversation with people. I use slang and if I am talking among friends of a subject and an evesdropper someone pipes in with something unrelated.... what would you do? (oops-->)that is kinda what it is like when they poke in just to find a place to deposit two cents. Anyway thanks for the help if I dont get kicked off of here then maybe we can have some fun, learn some stuff, and come up with some good recipes. Enough of this "just do what the book says and keep your head down young man!!" Its not like if I cant post here then I will stop shooting and loading! " 'Cause... I like shootin' though." __________________ Gimme Th'm Nannerz

May 21, 2009, 04:59 AM	#12
glokmunkee Member Join Date: April 25, 2009 Posts: 50	Mr. Watson (that looks wierd can I call you Jim?) I know you shoot .45 but can I ask if you shoot 9mm and have any SWC .355 on hand? It would be nice to know the length of that bullet. Would it be a 125gr? I would like to know how deep in the case the bullet will seat pushing the ogive out that far. There is no way to get a round nose that far out if fails at the mag! I have found that not exactly touching should serve the same purpose of reducing what I call the funnel effect when the bullet enters the bore. (which is what i come to be concerned with as a cause of keyholes? not barrel realted of course) I have fired several different depths and loads and am not able to replicate one but I havent pushed the envelope either. But do i plan to load up some more aggressive rounds. Do keyholes become a problem at higher velocities or lower ones? I only have so many of these bullets and I dont want to spin em off in the dirt. Thanks. __________________ Gimme Th'm Nannerz

May 21, 2009, 05:31 AM	#13
Sport45 Senior Member Join Date: May 25, 1999 Location: Too close to Houston Posts: 4,196	Keyholing with handgun rounds is generally a result of using a bullet that doesn't have enough diameter to engage the rifling. Using 9mm bullets in a .38 special comes to mind. HBWC can also keyhole if loaded backward and fired more than 10 yards or so because the heavy end wants to be in front. I suppose a barrel that is leaded to the point of the rifling being invisible to the bullet could do it, but you'd have bigger problems then. Keyholing is more often seen in rifles when the rifling twist rate is not adequate to stabilize the bullet. I don't believe you will experience keyholing with your 9mm as long as you are using .355" jacketed or .356" cast bullets. Seating depth will have no effect on this. A 6" target at 10 yards shouldn't be a problem and different seating depths will not put you off a target that size. The normal cautions apply if you are shooting cast bullets in a Glock with polygonal rifling. __________________ Proud member of the NRA and Texas State Rifle Association. Registered and active voter. Last edited by Sport45; May 21, 2009 at 05:36 AM.

May 21, 2009, 05:42 AM	#14
glokmunkee Member Join Date: April 25, 2009 Posts: 50	Good news! Thanks you caught me too. I said .355 i got them backwards. Sorry. But you raise a question. I understand that I will more than likely not ditch any rounds but you said that keyholes occur when there is not enough rifling to stabilize the bullet, well twist rate to be precise. So are you saying the rifling is not tight enough for that bullet at that velocity but would be at another? This in my mind relates to my short barrel. Reducing the stability of the bullet. I dont want any even slightly sideways. Wasted energy. Would I be able to tell from the gel? __________________ Gimme Th'm Nannerz

May 21, 2009, 05:47 AM	#15
Sport45 Senior Member Join Date: May 25, 1999 Location: Too close to Houston Posts: 4,196	The twist rate is a measure of how many inches of barrel length it takes for one complete revolution of the bullet. For instance, AR15's can be set up with anything from 1 turn in 12 inches (great for short, light bullets) to 1 in 7 (necessary to stabilize long, heavy bullets). Handgun bullets don't vary enough in length that I've ever seen the twist rate considered to be a factor. The length of the barrel really has nothing to do with accuracy. __________________ Proud member of the NRA and Texas State Rifle Association. Registered and active voter.

May 21, 2009, 06:14 AM	#16
glokmunkee Member Join Date: April 25, 2009 Posts: 50	I agree to the point that the barrel is just a starting point and the design of the bullet has more to do with accuracy after removing the human factor. The barrel length is debatable. I am not sure that I agree with you on that. I believe that there is an optimum barrel length for any bullet as well as velocity. As in fine tuning. Changing these variables requires compensation to get similar results. Not in target rounds but performance loads. To get the best your gun has to offer you for what it was designed for. It just seems that there are too many variables for it not to matter. __________________ Gimme Th'm Nannerz

May 21, 2009, 07:27 AM	#17
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,543	I do not have any 9mm SWCs, the place I used to get them from is out of business. Meister makes a 150 grain .356" SWC that is probably from the same number mould. I would not want one as light as 125 grains. The most keyholing and generally poor accuracy I have seen is from lightweight cast 9mm bullets. People worry too much about rifling twist in standard calibers. Most European 9mms have a 10" twist, many American guns have 16". Both do ok. Ed Harris had Barsto make a Browning barrel with the 18.75" twist of a .38 Special and it shot better than either.

May 21, 2009, 08:41 AM	#18
brickeyee Senior Member Join Date: December 29, 2004 Posts: 3,351	Unless you have fired thousands of practice rounds and can reliably hold on a 50 yard bullseye target to a few inches you are wasting tour time. It takes a long time to develop the proficiency needed to worry about things like bullets touching lands in a handgun affecting accuracy. Case length is easier to control if you are accurate enough to need it.

May 21, 2009, 03:16 PM	#20
brickeyee Senior Member Join Date: December 29, 2004 Posts: 3,351	Longer barrels improve sight radius if you are using iron sites. That alone improves accuracy since it reduces aiming error.

May 21, 2009, 05:43 PM	#21
glokmunkee Member Join Date: April 25, 2009 Posts: 50	J.W. So am I over simplifying to say that by increasing the twists per inch in a given length of barrel is (other than the actual pyhsics) like making a longer barrel out of a shorter one? This could indicate there is a given spin rate for a bullet too. __________________ Gimme Th'm Nannerz

May 21, 2009, 08:36 PM	#22
Sport45 Senior Member Join Date: May 25, 1999 Location: Too close to Houston Posts: 4,196	Let me google that for you. The Greenhill Formula is generally used to select "optimum" twist rate and it is a function of bullet length. And no, changing twist does not change the effective length of a barrel. Barrel length helps determine velocity and little else. As Brickeyee mentioned, handgun barrel length affects sighting if you use the factory sights. But adding barrel length that just sticks out the front of and autoloading pistol will not help accuracy. __________________ Proud member of the NRA and Texas State Rifle Association. Registered and active voter.

May 22, 2009, 06:04 AM	#23
glokmunkee Member Join Date: April 25, 2009 Posts: 50	Thanks! Thats a new one for me. I found some great sites that way! Unfortunately it has raised more questions than answers but I did find some answers luckily. The worst one ping ponging in my head is that a rifle bbl twist rate is discussed as one twist in so many inches. It is the same for my pistol. However a rifle has a 20 something inch barrel for the bullet to be supported as it turns a complete revolution or even two. Mine has 3.5 ". Thats like 3/8ths of a revolution in the barrel. I know theoretically at 8 inches the bullet will have turned one time whether in the barrel or not. Then the post that a barsto with increased twist rate helped accuracy and was done for a pro shooter. Barsto wont touch S&W centerfires anymore. I would like to have some barrels built, but. I think it would make a difference. (mm's can get really flingy out around 25 yrds and more at my power factor and makes me think of the cheap cross bows they sell at guns shows; how it flings the bolt and the fletch end kicks out to the side. Of course it straightens out. ) I would rather not up the power factor i like my recoil where it is. __________________ Gimme Th'm Nannerz

May 22, 2009, 09:33 AM	#25
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,543	Actually, that was a Barsto with a decreased twist rate. If you want a really minimal twist, Schuemann will make you a 9mm/.38 Super barrel with a 35" twist rate for light bullets - under 135 grains, they say.